Akiyama was born in Matsuyama Domain, Iyo Province, as a son of a poor samurai. As a youth, he studied literature, especially traditional waka poetry. The famous poet Masaoka Shiki was his friend from childhood. Later the two young men went to Tokyo to study literature and Akiyama began to prepare for entry into the Literature Department of Tokyo Imperial University. However, Akiyama was forced to abandon his study of letters as his elder brother Yoshifuru ordered him to go to Naval Academy in Tsukiji, Tokyo instead, largely due to the economically severe condition of the Akiyama family.

After his promotion to lieutenant on 24 October 1896, Akiyama was sent to the United States as a naval attaché from 26 June 1897 to 27 December 1899. It was a time of heightened tension between Japan and the United States, due to the overthrow of the Kingdom of Hawaii by American marines and settlers, which nearly led to a rupture of diplomatic relations.

On Akiyama's arrival in New York, he attempted to contact Alfred Thayer Mahan for advice and recommendations on how to study at either the US Naval Academy or Naval War College. Mahan was unwilling to help, aside from giving Akiyama a list of books to read. Akiyama then contacted the Assistant Secretary of the Navy, Theodore Roosevelt, but his pleas to be allowed to attend the Naval War College were refused.

Akiyama’s tour of duty coincided with the start of the Spanish-American War, and he joined the American fleet as a foreign military observer. He was able to watch American forces capture Santiago de Cuba in June 1898, and the blockade of Havana harbor in July. Akiyama submitted a lengthy report back to Japan on his observations, and noting problems in the blockade and landing operations. On conclusion of his tour, he served a short tour as a Naval Attache with the Japanese Embassy in Washington D.C..

In February 1899, due to the efforts of the Japanese ambassador, Akiyama received permission to serve a six-month tour on board a US Navy warship, the USS New York, where he was able to observe American tactics and fleet operations in the North Atlantic and Caribbean firsthand. As a result of his service on board, Akiyama participated in several lectures at the Naval War College in Newport, Rhode Island. On completion of his studies in the United States, Akiyama traveled to England from 27 December 1899 to 20 May 1900.

On his return to Japan, Akiyama was promoted to lieutenant commander on 1 October 1901 and assigned to various staff posts, and was the senior strategy instructor at Japan's Naval War College from July 1902-November 1903. Akiyama initiated a curriculum reform using hypothetical situations to simulate the formulation of orders and development of realistic contingency plans. He also introduced the concepts of wargaming and tabletop map exercises, and developed theories for a new strategic and tactical doctrines for the Japanese Navy based upon his observations during the Spanish-American War. Akiyama focused on Russia as the primary threat to Japan in his lectures.

Akiyama was 34 years old, and was lecturing to officers who were of the same age, or in some cases his senior. Nonetheless, he achieved the respect of his peers due to his professional knowledge, expertise and personality.[4]

With the outbreak of the Russo-Japanese War, Akiyama was promoted to commander on 1 September 1904, but remained on the planning staff, and was a close and trusted confidant of Japanese Commander in Chief of the Combined Fleet, Togo Heihachiro. Togo insisted that Akiyama accompany him into battle on his battleship Mikasa as an staff officer, and despite his junior rank Akiyama played a central role in planning for the Battle of Port Arthur, Battle of the Yellow Sea, and planning for arrival of the Russian Baltic Fleet and the subsequent Battle of Tsushima. The objective of Japanese navy in Battle of Tsushima was to destroy Russian fleets completely not to allow Russia for having influence on sea of Japan at any cost. He came up with a famous tactic, which is to change the advancing direction in front of enemy referring to an old book in the late twelfth century called Old Piratical Tactics of the Nojima School on Japanese pirates' tactics.[5] During the preliminary negotiations for the Treaty of Portsmouth, the Japanese government had designated Akiyama as the senior naval representative, but his mother's death led to his replacement.[6]

Akiyama was promoted to rear admiral on 1 December 1913. Soon afterwards, the Siemens-Vickers Naval Armaments Scandal of 1914 shook up the government, forcing the resignations of Yamamoto Gonnohyōe and Ōkuma Shigenobu. Akiyama remained one of the few senior officers completely untouched by suspicion or corruption, and was nominated by Yashiro Rokuro as Director-General of the Navy in an effort to restore public confidence. Akiyama served on the Imperial Japanese Navy General Staff until his retirement on 1 December 1917. His major accomplishment during this period was to have the Otowa stationed permanently at Shanghai, from which it helped support a large network of intelligence agents posing as exchange students in all corners of China. At the same time, Akiyama maintained a regular and secret correspondence with Sun Yat-sen, assisting him also materially in his efforts to prevent Yuan Shikai from establishing a new empire.[4]